The goal of this study is to test a transdisciplinary ecological approach to reducing mental health disparities among Mexican immigrants by adapting and integrating a multilevel community-based advocacy, learning, and social support intervention (Immigrant Well-being Project, IWP) into existing efforts at three community partner organizations that focus on mental health, education, legal, and civil rights issues for Mexican immigrants. This research is innovative and significant because it employs cutting edge strategies to address social-structural determinants of mental health and examines the community-engaged process of adapting and testing the impact of a multilevel intervention originally designed for refugees. The IWP intervention emphasizes a sustainable and replicable partnership model between community-based organizations and universities that involves Mexican immigrants and undergraduate advocates working together to: a) increase immigrants? abilities to navigate their communities; b) improve immigrants' access to community resources; c) enhance meaningful social roles by valuing immigrants' culture, experiences, and knowledge; d) reduce immigrants' social isolation; and e) increase communities? responsiveness to immigrants through changes in policy and practice. The IWP is administered by university students enrolled in a service learning course, and has two elements: 1) Learning Circles, which involve cultural exchange and one-on-one learning opportunities, and; 2) Advocacy, which involves collaborative efforts to mobilize community resources related to health, housing, employment, education, and legal issues. Studies of the intervention model with refugees demonstrated feasibility, appropriateness, acceptability, and evidence that the intervention decreased participants? psychological distress and increased protective factors, and impacted changes in system-wide policies and practices. After completing in-depth ethnographic interviews with 24 Mexican immigrant adults to elucidate their mental health needs, stressors, current political/economic/social context, and local solutions, and a process of community engagement and intervention adaptation, a mixed methods strategy with data collected from 90 participants at four time points over a period of 14 months will be used to test the impact of the 6- month intervention on reducing psychological distress, increasing protective factors (access to resources, English proficiency, environmental mastery, and social support), and achieving system-level changes in organizational, local, and state policies and practices that impact Mexican immigrants? well-being. Mechanisms of intervention effectiveness will be explored by testing mediating relationships between protective factors and psychological distress. Qualitative data will explore feasibility and acceptability of the intervention, participants? experiences in the intervention, and unexpected impacts; document multilevel changes and the context of implementation at each site; and inform interpretation of quantitative data. Quantitative and qualitative data on the quality of the CBPR partnerships and their relationship to multilevel outcomes will also be examined.